$
vlsm-calc 192.168.1.0/24
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VLSM Calculator
Enter your network address and define multiple subnets with different host requirements to calculate an efficient VLSM allocation plan. Get optimized variable-length subnet masks, network addresses, broadcast addresses, and usable host ranges for each subnet — maximizing IP address utilization across your network.
Network Configuration
Allocation Summary
Total Required
0
Total Allocated
0
Remaining
254
Efficiency
0%
Address Space Usage
0%
What is VLSM?
Variable Length Subnet Mask (VLSM) allows you to use different subnet masks for different networks within the same address space. This results in more efficient IP address allocation compared to classful networking or fixed-length subnet masks.
VLSM works by allocating larger subnets first, then filling in the remaining space with smaller subnets. This "best fit" approach minimizes wasted IP addresses.